The present invention relates to a quench arrangement for tempering hot shaped glass sheets and in particular to a quench arrangement that allows hot glass sheets to bypass a cooling station without upsetting the continuous flow of glass sheets through a glass sheet processing line.
In one method of shaping a glass sheet to a contoured configuration, the sheet is heated and engaged by an upper mold having the desired shape of the glass. The shaping may be supplemented by a complimenting lower mold that lifts and presses the glass sheet against the upper mold. After shaping, the glass sheet is transferred to a cooling station where the glass is rapidly quenched, i.e. tempered, by applying air blasts against the opposing major surfaces of the sheet. This transfer of the glass may be accomplished by depositing the shaped sheet onto a contoured support ring of a type well known in the art that moves between the shaping station and the cooling station.
In processing a series of glass sheets, problems may arise that adversely affect the operation of the entire line. More specifically, problems such as broken glass sheets or non-functioning shaping molds must be dealt with immediately because of the continuous flow of heat softened glass sheets through the system. If the glass sheet flow is slowed or stopped, glass sheets in the furnace may overheat and sag between or stick to the furnace conveyor rolls. As an alternative, the cooling station may be positioned alongside the shaping station rather aligned along the centerline of the furnace and shaping station so that the glass sheet may pass directly through the shaping station and into a collection bin. However, in some situations the cooling station is preferably linearly aligned with the glass sheet heating furnace and shaping station. More particularly, aligning the cooling station with the furnace and shaping station allows the glass sheet to be shaped to travel with its short dimension oriented along the centerline of the furnace. This in turn allows for zone heating of the glass sheet across its width. In addition, orienting the sheet in the short direction reduces the time required for the sheet to pass from the furnace into the shaping station and from the shaping station into the cooling station. With this type of heating/shaping/cooling arrangement, if the glass sheet is allowed to pass through the shaping station without being shaped and transferred onto a support ring, it would impact the quenches in the cooling station, resulting in broken glass which must be removed by an operator before the next glass sheet arrives. An operator may attempt to remove the hot glass sheet at the shaping station; however this provides a hazard to the operator because of the extremely high temperatures. In addition, if the glass sheet breaks in the shaping station, the glass fragments must be removed from the rolls and between the molds before the next glass sheet arrives.
It would be advantageous to provide a quench arrangement whereby glass may be unloaded from the line in the event of an operating problem without adversely affecting the serial flow of glass sheets through the line and without operator assistance.